At some point each developer must check his or her code into the source control system to see whether it will work with all the code others have written and checked in.
The point of a pull system is to use a kanban board to limit work-in-progress by pulling from the previous phase of your value stream when necessary.
拉动系统的要点是在需要的时候通过拉动前期的价值流，利用看板来限制在制品的数量。
3
Part of what’s going here is that the computer operating system has achieved a level of maturity and efficiency. You could even say that work on the OS has reached a point of diminishing returns.
这里面临的一个问题在于，计算机操作系统已经实现了一定的成熟度和效率，我们甚至可以说，对操作系统的使用已经达到了收益递减点（Point of Diminishing Returns）。